Mechanical Components

Reverse Pressure Capable Finger Seal

Each finger seal consists of a number of multiple thin metal laminates, each with a multitude of flexible projections that are referred to as “fingers.” To form a functional seal, multiple laminates are formed into a stack, with each laminate oriented so that the slots between its fingers cover the slots of the neighboring laminates. For protection and support of the laminates, forward and aft cover plates are placed on each side of the finger seal stack. A high pressure exists on one side of the seal, providing a driving force to push the air from one side of the seal to the other.

Posted in: Briefs, Mechanical Components, Coatings Colorants and Finishes, Seals and gaskets

Reactive Structure and Smart Armor for Future Ground Vehicles

AReactive Structure Technology (RST) is a new class of smart structure that can react to external excitations (such as blast or ballistic impacts) in a carefully designed way using the energy pre-stored internally or from the external excitations to counteract the hazardous loading or perform other desired tasks. A reactive structure deflects an incoming projectile in order to protect a vehicle body. When a projectile hits the face plate (armor), the embedded sensors feed the impact signal to a control unit, and actuators are triggered to move the faceplate. The movement of the faceplate deflects the projectile and significantly reduces the possibility of penetration in the back plate.

Posted in: Briefs, Mechanical Components, Sensors and actuators, Active safety systems, Protective structures, Military vehicles and equipment

Variable-Thrust, Multiple-Start Hybrid Motor Solutions

Interceptor boost propulsion has traditionally been dominated by solid rocket systems due to their responsiveness and high mass fraction capabilities. However, increased costs of handling these flammable motors, the need to evolve more and more insensitive munitions, the static thrust profile created at propellant casting, and the inherent performance limitations of solid propellants have motivated the interest in exploring alternate technologies.

Posted in: Briefs, Mechanical Components, Solid propellants, Product development, Hybrid engines

Wheel Force Transducer

Aconcept wheel force transducer has been developed that can measure the forces and moments between a tire and a road on a High Mobility Multi-purpose Wheeled Vehicle (HMMWV or Humvee) driven under off-road conditions. The proposed wheel force transducer is an important step in correcting the gap in current tire testing and modeling knowledge to ensure that future off-road vehicle models and simulation efforts are conducted with confidence. In order to obtain tire characteristics over off-road terrain, cost-effective field test equipment was required.

Posted in: Briefs, Mechanical Components, Tires and traction, Wheels, Test equipment and instrumentation, Off-highway vehicles and equipment

Nozzles for Focusing Aerosol Particles

Several nozzles have been designed to aerodynamically focus aerosol particles into a small-diameter jet, so that individual particles can be illuminated by a laser beam and their light scattering and/or laser-induced fluorescence (LIF) spectra can be measured. An additional nozzle can aerodynamically puff selected particles out of the airstream so that they can be sorted and collected.

Posted in: Briefs, Mechanical Components, Nozzles, Test procedures, Aerodynamics

Parallel Hybrid Vehicles Using Fuzzy Logic Control

A fuzzy logic controller for hybrid vehicles with parallel configuration was proposed. Using the state-of-charge (SOC) of the energy storage, the driver command, and the motor/generator speed, a set of rules was developed. The fuzzy logic controller can determine the split between the electric motor and the internal combustion engine to achieve better fuel economy and low emission performance without losing vehicle performance.

Posted in: Briefs, Mechanical Components, Fuzzy logic, Architecture, Hybrid electric vehicles, Vehicle performance

Membrane Pump for Synthetic Muscle Actuation

A synthetic muscle has been developed that uses inflatable balloons to produce a tensile force from a positive pressurization. Mechanical supply and ducting is used to provide the required pressurization. However, the mechanical supply and ducting that is currently used is limited in several respects. To optimize rate of actuation, it is desirable to minimize the cell volume and to maximize the area through which fluid is forced into the cell. Ideally, a fully closed cell that is inflated through some mass transfer process that takes place through the cell boundary would lead to a maximum cell response rate.

Posted in: Briefs, Mechanical Components, Architecture, Sensors and actuators, Pumps, Marine vehicles and equipment

Nonlinear, High-Fidelity, Aeroelastic Analysis for Novel Configurations

Efforts to develop morphing air vehicles with multiple mission capabilities have recently been undertaken by several research teams, including NASA’s Aircraft Morphing program and the Defense Advanced Research Projects Agency’s (DARPA) Morphing Aircraft Structures program. One such morphing wing structure is the folding wing concept. With multiple individually articulated sections, various wing geometries can be achieved in-flight, allowing for multirole missions with the same aircraft.

Posted in: Briefs, Mechanical Components, Wings, Vehicle styling, Aircraft, Military aircraft

Designing a Sensorless Torque Estimator for Direct Torque Control of an Induction Motor

Induction motors often are the preferred choice among industrial motors due to the modern power electronics that improve their speed control. Vitally important for the speed control of a motor is the accurate estimation of the magnetic flux and the electromagnetic torque. Knowing the electromagnetic torque of a motor, one is able to control it and thus monitor the speed faster and more stably.

Posted in: Briefs, Mechanical Components, Measurements, Power electronics, Industrial vehicles and equipment

Lightcraft Propulsion for Launching a Small Satellite

A study of lightcraft propulsion systems in general has led to the conception and analysis of such a system for launching a small (having a mass no more than a few kilograms) satellite into a low orbit around the Earth. This study built on theoretical and experimental investigations of the feasibility of lightcraft, performed by a number of researchers during the past two decades. The word “lightcraft” signifies an aircraft or spacecraft that derives its propulsive energy from a laser beam aimed toward it from an external platform that, for the purpose of the present study, would be a ground station.

Posted in: Briefs, Mechanical Components, Mirrors, Lasers, Propellants, Satellites